Linear image sensor

Abstract

A linear image sensor includes N arrays of photoelectric converting pixels, wherein N is an even integer at least equal to 2. Each array is formed by arranging, with a predetermined pixel pitch in a first direction of the array, a plurality of pixels, and each of the pixels is so shaped that the area per unit length of the pixel decreases progressively from the center of the pixel both in the first direction of the array and in a second direction perpendicular to the first direction. The N arrays themselves are provided with a mutual distance from each other of M/2 times the pixel pitch in the second direction and are mutually displaced by 1/N of the pixel pitch in the first direction so as to form a mutually interpolating arrangement, wherein M is a positive integer equal to at least 1 and wherein M and N are independent of each other.

What is claimed is: 
     
       1. A linear image sensor comprising n arrays of photoelectric converting pixels, wherein n is an even integer at least equal to 2, each said array being formed by arranging, with a predetermined pixel pitch in a first direction of said array, a plurality of pixels, each of which pixels is so shaped that an area per unit length of said pixel decreases progressively from the center of said pixel both in the first direction of said array and in a second direction perpendicular to the first direction, wherein said n arrays are provided with a mutual distance from each other of m/2 times said pixel pitch in the second direction and are mutually displaced by 1/n of said pixel pitch in the first direction of said array so as to form a mutually interpolating arrangement, wherein m is a positive integer equal to at least 1 and wherein m and n are independent of each other.   
     
     
       2. A linear image sensor according to claim 1, wherein each of said pixels has a normal polygonal shape. 
     
     
       3. A linear image sensor according to claim 1, wherein each of said pixels has a circular shape. 
     
     
       4. A linear image sensor according to claim 1, further comprising: reading means for reading an image signal from each of said n arrays of photoelectric converting pixels;   delay means for delaying the image signal, read by said reading means, corresponding to said mutual distance of the arrays;   shift means for shifting a phase of the image signal corresponding to said pixel pitch; and   synthesizing means for synthesizing the image signal delayed by said delay means and the image signal subjected to phase shifting by said shift means.   
     
     
       5. A linear image sensor according to claim 4, wherein each of said pixels has a normal polygonal shape. 
     
     
       6. A linear image sensor according to claim 4, wherein each of said pixels has a circular shape. 
     
     
       7. A linear image sensor according to claim 4, wherein said reading means is adapted to read the image signal of a line from said arrays of the photoelectric converting pixels within a predetermined period, and said delay means is adapted to delay the image signal by m times said predetermined period. 
     
     
       8. A linear image sensor according to claim 7, wherein each of said pixels has a normal polygonal shape. 
     
     
       9. A linear image sensor according to claim 7, wherein each of said pixels has a circular shape. 
     
     
       10. A linear image sensor according to claim 7, wherein said shifting means is adapted to shift the phase of said image signal by 2 π/n. 
     
     
       11. A linear image sensor according to according to claim 10, wherein each of said pixels has a normal polygonal shape. 
     
     
       12. A linear image sensor according to according to claim 10, wherein each of said pixels has a circular shape. 
     
     
       13. A linear image sensor according to claim 1, further comprising: reading means for reading an image signal from each of said n arrays of photoelectric converting pixels;   A/D conversion means for converting an output of said reading means into a digital image signal;   a memory for storing at least one line of the digital image signal converted by said A/D conversion means; and   latch means for latching, at a predetermined timing, the digital image signal stored in said memory or the digital image signal released from said A/D conversion means.   
     
     
       14. A linear image sensor according to claim 13, wherein said reading means is adapted to read the image signal of each line from said arrays of the photoelectric converting pixels within a predetermined period, and said memory is adapted to store said digital image signal by a delay time corresponding to m times said predetermined period. 
     
     
       15. A linear image sensor according to claim 13, wherein said latch means is adapted to so latch the digital image signal stored in said memory and the digital image signal released from said A/D conversion means that said digital image signals are mutually shifted in phase by 2 π/n. 
     
     
       16. A linear image sensor according to claim 13, wherein each of said pixels has a normal polygonal shape. 
     
     
       17. A linear image sensor according to claim 14, wherein each of said pixels has a normal polygonal shape. 
     
     
       18. A linear image sensor according to claim 15, wherein each of said pixels has a normal polygonal shape. 
     
     
       19. A linear image sensor according to claim 13, wherein each of said pixels has a circular shape. 
     
     
       20. A linear image sensor according to claim 14, wherein each of said pixels has a circular shape. 
     
     
       21. A linear image sensor according to claim 15, wherein each of said pixels has a circular shape.